1. Field of the Invention
The present invention relates to a method and apparatus for medical instruments and more particularly a cleaning method and apparatus for removing deposits on metallic instruments used in dental treatment.
2. Description of the Prior Art
Heretofore, in dental treatment, there have been used various metallic instruments, including stopper, probe, excavator and pincette, for applying a medicine to an effected part of a patient, grinding a tooth, filling a tooth with a temporary sealant, or fixing a tooth crown through an adhesive. Since the materials which have been used in the dental treatment are deposited on those instruments, the instruments are washed after use to remove such deposits and keep the instruments in good hygienic condition.
As the aforesaid temporary sealant or adhesive there usually is employed cement which has a strong adhesive force. When such a highly adherent material is deposited on a medical instruments it is removed by using a dedicated cleaning apparatus.
According to the said cleaning apparatus, medical instruments which have been used in medical treatments and with deposits thereon can be washed together, and as this type of a cleaning apparatus there is known an ultrasonic washing apparatus wherein a washing basket containing medical instruments is immersed in a washing vessel containing a washing solution and ultrasonic waves are fed by turning a switch ON to effect cleaning automatically (see, for example, U.S. Pat. No. 4,710,233, U.S. Pat. No. 3,937,236 and U.S. Pat. No. DES. 3,934,928).
Also known is an ultrasonic washing apparatus comprising a plurality of vessels and which automatically performs not only washing of medical instruments but also rinsing and drying of the washed instruments (see, for example, Japanese Patent Laid Open No.115680/81). According to this known apparatus, a rinsing vessel for rinsing medical instruments after washing and a drying vessel for drying the rinsed instruments, in addition to a washing vessel for washing medical instruments using ultrasonic waves, are arranged side by side in a row within the same apparatus, and medical instruments contained in a washing basket are conveyed to those vessels successively by means of conveyance mechanism.
However, such conventional ultrasonic washing apparatus are generally low in their washing capacity, so with ultrasonic washing alone it is impossible to thoroughly wash off deposits having a strong adhesive force, and deposits will remain on the washed medical instruments thus requiring a manual operation for removing them which operation is troublesome. The latter ultrasonic washing apparatus comprising plural vessels also involves the problem that the size of the apparatus increases with increase of the floor space, because plural vessels are arranged side by side in a row within the same apparatus.
Besides, in the latter ultrasonic washing apparatus, since the ultrasonic washing vessel and the rinsing vessel each require a water supply pipe, a water discharge pipe and an overflow pipe for the prevention of water overflow, the piping becomes complicated and the piping space expands. Further, when the operations for maintenance and for mounting are also taken into account, a wide space is required. This point is also a cause of the increase in the size of the apparatus.